Stealth 91, if you will be living it in the winter this would be a suggestion. I am from SW Iowa and -25 is not unusual especially in January. I would get straw bales and put them under the perimeter of the RV, pack them in tight. A low wattage heat lamp under the RV would help, just be careful where you place it. You will need to heat trace your fresh water line if where you are staying will have water available in winter. If you will not be moving for 3 months you should get a larger propane tank rented, 100 gal+. No need to do anything about the waste water lines since they can be left unhooked until needed. Best, just hope for a mild winter. On very cold nights open cabinet doors where water lines may be. I'm sure there will be others on the forum that have already experienced living in very cold climate.
2014 Palomino Puma 25RS
2011 F-150 Super Crew XLT
Days camped in 2014 - 23
Camped 2015 - 47
Camped 2016 - 51 done - 6 more planned so far